Facebook topped Google's search engine as the most popular web site in the U.S. for the second year running, and it's growing faster than Google, too.

Experian Hitwise reports that Facebook.com made up 10.29% of all web visits between Jan. and Nov. 2011. That's an increase of 15% last year. Google.com made up 7.70% of all visits, up only 7% from last year.

But Google was saved by YouTube, which moved up two places from last year into the number three spot, and Gmail, which entered the top ten for the first time.

Overall, Google properties made up 11.29% of all visits, versus 8.90% for Facebook.

Ironically, four of the top ten search terms entered were about Facebook, as also happened last year. In other words, about 4% of all searches are users simply trying to figure out how to get to Facebook. No wonder Google had to respond with Google+.